JP2011512718A - Automatic management of inter-RAT / frequency adjacency list - Google Patents

Abstract

In one of its aspects, the present technology relates to a method of operating a communication system (10) comprising a serving radio base station (50 _S ) and a candidate radio base station (50 _C ). The serving radio base station (50 _S ) includes a radio base station to which the radio mobile device (30) provides a measurement report. The serving radio base station (50 _S ) and the candidate radio base station (50 _C ) are different in at least one of frequency and radio access technology. The method comprises the step of allowing the serving radio base station (50 _S ) to allow the mobile device (30) to acquire information broadcast from the candidate radio base station (50 _C ). The information is information for specifying the cell global ID (CGI) of the candidate radio base station (50 _C ) or the cell global ID (CGI) of the radio base station itself. The mobile station (30) acquires information from the candidate radio base station (50 _C ) during at least one reading gap. The read gap is a period in which the mobile device (30) does not receive information from the serving radio base station (50 _S ).

Description

  The present invention relates to communication, and more particularly, to inter-radio access technology (IRAT) measurement and inter-frequency measurement related to management of an adjacency list.

  This application claims the priority of US Provisional Patent Application No. 61 / 023,469 entitled “Automatic Management of Inter-RAT / Frequency Adjacency List” filed on January 25, 2008, and its entire contents. Is incorporated herein by reference.

  In a typical cellular radio system, a radio terminal (also known as a mobile device and / or user equipment unit (UE) or both) communicates with one or more core networks via a radio access network (RAN). A wireless terminal may be a mobile device or user equipment unit (UE), such as a mobile phone (“cellular” phone) and a laptop computer with wireless capabilities (eg, a mobile terminal), and thus, for example, portable, pocket, handheld, It may be a mobile device that communicates voice and / or data with a radio access network, either on a computer or on-board.

  A radio access network (RAN) covers a geographical area divided into cell areas, and each cell area is served by a base station such as a radio base station (RBS). The base station is also referred to as “Node B” or “B Node” depending on the network. A cell is a geographical area where radio base station equipment at a base station site provides radio coverage. Each cell is identified by an ID in the local radio area that is broadcast within the cell. The base station communicates with user equipment units (UEs) within range of the base station through an air interface that operates at radio frequencies.

  In some versions (especially early models) of radio access networks, several base stations are usually connected to a radio network controller (RNC) (eg, via landline or microwave). Yes. A radio network controller, sometimes referred to as a base station controller (BSC), manages and coordinates various operations of a plurality of base stations connected thereto. A radio network controller is typically connected to one or more core networks.

  UMTS (Universal Mobile Telecommunication Systems) is a third generation mobile communication system that evolved from GSM (Global System for Mobile Communications) and provides improved mobile communication services based on wideband code division multiple access (WCDMA) access technology. Is intended. UTRAN is essentially a radio access network that uses wideband code division multiple access for user equipment units (UEs). The Third Generation Partnership Project (3GPP) is working to further evolve UTRAN and GSM based radio access network technologies.

  Specification work on E-UTRAN (Evolved Universal Terrestrial Radio Access Network) is underway within the 3rd Generation Partnership Project (3GPP). E-UTRAN includes LTE (Long Term Evolution) and SAE (System Architecture Evolution).

  Inter-radio access technology (RAT) handover is the first in which a mobile terminal has a second radio access technology (such as UTRA) from the use of a first radio access system that has a first radio access technology (such as GSM). This is a process of switching to the second wireless access system. Inter-RAT handover is typically initiated when the quality of the downlink radio connection of the first radio access network falls below a certain level. For inter-radio access technology (RAT) handover, for example, entitled “COMMANDING HANDOVER BETWEEN DIFFERING RADIO ACCESS TECHNOLOGIES”, which is incorporated herein by reference in its entirety. U.S. Pat. No. 7,181,218.

  LTE (Long Term Evolution) is a variation of 3GPP radio access technology, which directly connects a radio base station node to a core network rather than a radio network controller (RNC) node. In general, in LTE, the function of a radio network controller (RNC) node is performed in a radio base station node. Under these circumstances, the LTE system radio access network (RAN) essentially has a “flat” architecture with radio base station nodes that do not report to radio network controller (RNC) nodes.

  E-UTRAN (Evolved UTRAN) provides E-UTRA (Evolved UTRA) user plane and control plane protocol terminations to user equipment units (UE), e.g. evolution such as evolved Node B or eNB Type base station node. The eNB hosts the following functions (although there are other functions not listed): They include (1) radio resource management (eg, radio bearer control, radio admission control), connection mobility control, dynamic resource allocation (scheduling) functions, (2) delivery of paging messages to eNBs, etc. Mobility management entity (MME) and (3) user plane entity including IP header compression and user data stream encryption, termination of U-plane packet for paging reason, and switching of U-plane for UE mobility support (UPE). The eNB hosts the physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, and packet data control protocol (PDCP) layer, including user plane header compression and encryption functions. The eNodeB also provides a radio resource control (RRC) function corresponding to the control plane. eNodeB manages radio resource, admission control, scheduling, negotiated UL QoS implementation, cell information broadcast, user plane and control plane data encryption / decryption, and DL / UL user plane packet header compression / Perform many functions, including decompression.

  2G and 3G systems including E-UTRAN use Mobile Assisted Handover (MAHO). Each mobile station (MS) regularly monitors the signal quality of the base stations around its own base station in addition to the signal quality of the base station (BS) that is providing the service, and the measured values are being provided. You may report to a wireless base station. A wireless network typically initiates a handover based on these measurements. As an example, consider the case where E-UTRAN is ready for handover (HO). The target or candidate base station (BS) that takes over the mobile device (MS) provides the mobile device (MS) with guidance on how to perform wireless access such as radio resource setting and necessary IDs. In addition, the serving base station (BS) needs to transfer user plane data to the target base station (BS), which must know the target base station (BS) and This means that a unique ID, the so-called cell global ID (CGI), must be established before HO is executed.

  There is usually also a local identifier (ID) defined for each base station (BS). The local ID of the base station (BS) is not unique within the network because it is used for Layer 1 measurements and is not long enough. For example, the mobile station (MS) reports the signal quality of the base station (BS) together with its local ID to the serving base station (BS). Local IDs do not satisfy handover (HO) requirements because they are not unique within the network. From such a situation, when taking a mobile station (MS) to an adjacent base station, it is necessary to know the CGI of the adjacent base station. Therefore, the neighbor relation list (NRL) maps the local ID to the cell global ID (CGI), and possibly other information such as the IP address of the target base station (BS). Configure or at least participate in it.

  It is envisioned that the E-UTRAN radio coverage would initially be limited. In order to provide seamless mobility, a mobile station (MS) in E-UTRAN can be moved to an alternative radio access technology (RAT) such as GERAN (GSM EDGE Radio Access Network) or UTRAN with good coverage. It is necessary to perform a handover (HO). It is also desirable to switch to E-UTRAN as soon as a mobile station (MS) served by 2G (eg GERAN) or 3G (eg UTRAN) enters E-UTRAN coverage. This is desirable because E-UTRAN provides higher data rates and enables services that require wider bandwidth. A handover between two different RATs is called an inter-RAT (IRAT) handover. LTE is also planned to operate in multiple frequency bands. To deal with issues such as load balancing between different frequency bands that require inter-frequency handover (HO), IRAT and inter-frequency adjacency lists (NRL) are created.

  One focus of the E-UTRAN standardization work is to ensure that new network deployment is simple and cost effective to operate. The idea is that the new system is self-optimizing and self-configuring in as many aspects as possible. For example, see 3GPP TR 32.816 “Study on Management of E-UTRAN and SAE”.

For inter-RAT / inter-frequency HO, the serving base station (BS) needs to be able to trigger inter-RAT / inter-frequency measurements, compare different RATs / inter-frequency, and determine HO. is there. To prepare for HO from a serving base station (BS) to a target base station (BS) (eg, from an E-UTRAN base station to a UTRAN base station), as shown in FIG. Events usually need to take place (both axes represent the quality of the serving BS and the quality of the candidate BS).
If the signal quality estimate of the serving base station (BS) falls below a certain threshold (threshold A in FIG. 13), an inter-RAT / inter-frequency measurement performed by the mobile station (MS) is triggered.
If the signal quality estimate of the serving base station (BS) rises above a certain threshold (threshold A in FIG. 13), the inter-RAT / inter-frequency measurement performed by the mobile station (MS) is stopped.
The signal quality estimate of the serving base station (BS) is below a certain threshold (threshold A in FIG. 13) and the signal quality estimate of the candidate base station (BS) is below the threshold (B in FIG. 13) If so, a RAT / inter-frequency HO procedure may be initiated.

  For a mobile station (MS) having only one receiver, the reception frequency of the mobile station (MS) must be changed when performing inter-RAT / inter-frequency measurements. When the frequency is changed (during RAT / inter-frequency measurement), the mobile station (MS) cannot communicate with the RAT that is providing the service. The state in which the mobile station (MS) is performing inter-RAT / inter-frequency measurements is called a read gap. A serving base station may avoid transmission to a mobile station (MS) during a read gap. The state in which the base station does not transmit to the mobile station (MS) is called a transmission gap. Note that a read gap must be issued in order for the mobile station (MS) to make inter-RAT / inter-frequency measurements using the time of the transmission gap. From now on, when a serving base station (BS) issues a transmission gap, it is assumed that the associated mobile station (MS) always issues a reading gap. However, even if the base station (BS) has not issued a transmission gap, the mobile station (MS) may issue a reading gap. The gap may occur periodically according to a predetermined pattern as shown in FIG. 14, or may be triggered by an event. The length of the gap may be fixed or variable.

  Some RATs, such as E-UTRAN and UTRAN, support dynamic scheduling of uplink (UL) and / or downlink (DL) data, where the radio resource is the user's instantaneous Assigned to users and radio bearers according to traffic demand, QoS requirements, and channel quality estimates. The base station (BS) may allocate time or frequency radio resources to, for example, a mobile device with higher channel quality. The smallest schedulable resource entity is hereinafter referred to as a scheduling block (SB).

  As an example, in E-UTRAN, the scheduling block (SB) comprises two consecutive resource blocks, the total length is 1 ms, and the bandwidth is 180 kHz. See FIG. In this case, the base station (BS) assigns the SB to the mobile device in both time and frequency. In E-UTRAN, a mobile station (MS) may be configured to report a channel quality indicator (CQI) report indicating the quality of the DL. Based on the CQI report and QoS requirements, the scheduler allocates SBs.

US Pat. No. 7,181,218 International application PCT / EP2007 / 001737

3GPP TR 32.816 “Study on Management of E-UTRAN and SAE” 3GPP TS 45.002 “Multiplexing and multiple access on the radio path” 3GPP TS 25.331 “Radio Resource Control (RRC): Protocol specification”

  In the past, 2G (eg, GERAN) and 3G (eg, UTRAN) systems have deployed NRL lists using coverage prediction using a planning tool prior to base station (BS) installation. Due to prediction errors due to terrain data and wave propagation model inaccuracies, the operator will need to fully explore the coverage area to identify all handover areas and adjacent base stations from such situations. You are forced to do a test by walking. As the wireless network evolves over time with new cells and changes in the interference environment, NRL conventional planning requires iterative iterations of the planning procedure. This has proven to be expensive and new methods are needed to automatically derive NRL. Therefore, it is essential to use a method that can be done automatically during operation to create and update the NRL.

  Known existing solutions aimed at automating NRL management deal with only one specific RAT, for example GERAN or UTRAN. See, for example, PCT / EP2007 / 001737, a PCT patent application filed February 28, 2007, the entire contents of which are incorporated herein by reference. For one type of RAT, NRL management has been automated, but the problem of NRL creation for different RAT / frequency has not been solved so far. Traditionally, these inter-RAT / inter-frequency NRLs have been derived manually using geographic information and vehicle / walking tests. This has proven to be quite tedious and expensive, and new automated methods are needed where the network itself creates and configures the NRL.

  Therefore, what is needed and one object of the present invention is to create and manage inter-RAT measurements and information as used in adjacency lists for inter-RAT / frequency mobility. Apparatus, method and technique for doing so.

The present technology is an apparatus, method and technique for automatically managing relationships with neighboring base stations of other RAT / frequency, such as a neighbor relation list (NRL) having neighboring base stations of GERAN and UTRAN in E-UTAN. I will provide a. The present technology includes the following.
Method and apparatus for detecting new inter-RAT / inter-frequency neighbor base stations using mobile station (MS) measurements-Little or no disruption of ongoing traffic on the serving RAT / frequency In particular, a method and apparatus for retrieving the CGI of a neighboring base station (BS)-method and apparatus for verifying a new neighboring base station and updating an NRL. The present technology is for example for seamless movement between RATs / frequency. In terms of the planning and maintenance of the inter-RAT / inter-frequency NRL required for the system, it has the advantage of reducing operator costs.

  In one of its aspects, the present technology relates to a method of operating a communication system comprising a serving radio base station and a candidate radio base station. A radio base station that is providing a service includes a radio base station from which a radio mobile device provides a measurement report. The serving radio base station and the candidate radio base station are different in at least one of frequency and radio access technology. The method includes the step of allowing the serving radio base station to obtain information broadcast from the candidate radio base station to the mobile device, and the mobile device obtains information from the candidate radio base station during at least one reading gap. A process. The information is information for specifying (locating) the cell global ID (CGI) of the candidate radio base station, or the cell global ID (CGI) of the radio base station itself. The reading gap is a period during which the mobile device does not receive information from the serving radio base station.

  Information may take various forms. For example, depending on the content and timing, the information may include synchronization information of candidate radio base stations, local identification information of candidate radio base stations, information for specifying a cell global ID (CGI) of candidate radio base stations, or a cell global ID Even (CGI) itself may be sufficient.

  In the first embodiment and the implementation mode, a method is provided in which a serving radio base station provides a transmission gap to a mobile device (the transmission gap has a predetermined period during which the mobile device can acquire information from candidate radio base stations). A step of issuing, and a step of the mobile device acquiring information from the candidate radio base station during the transmission gap.

  In a modification of the first embodiment and the implementation mode, the mobile device reads at least one radio base station that is providing the service (having a predetermined period during which the mobile device can acquire information from the candidate radio base station). In response to the notification that the gap is to be issued, the radio base station providing the service issues a transmission gap to the mobile device.

  In the second embodiment and the implementation mode, the method includes a step of allowing a serving radio base station to start a transmission gap and allowing a mobile device to obtain information broadcast from a candidate radio base station; The wireless base station further includes a step of terminating the transmission gap as soon as information from the mobile device is received.

  In a second embodiment and a variant of the implementation mode, the mobile device requests a serving radio base station to issue a transmission gap, and as soon as it requests, the mobile device reads the read gap to obtain information. To start.

  In the third embodiment and mode of implementation, the method includes a periodic transmission gap of fixed length to a mobile station by a serving radio base station (e.g., at least one transmission gap is information in the candidate radio base station). Are aligned with the broadcast frame of the candidate radio base station that is broadcasting the message, and the mobile station obtains information during one transmission gap of the periodic transmission gaps.

  In the fourth embodiment and implementation mode, the method includes the step of the mobile station issuing at least one read gap to obtain information from the candidate radio base station, and from the serving radio base station during the read gap. And ignoring the transmission of. In a fourth embodiment and extension of implementation mode, the mobile comprises further recovering frames lost during at least one read gap using an iterative request procedure.

  Alternatively, the non-reception of a predetermined report from the mobile device indicates that the mobile device is emitting at least one reading gap, and communication between the serving radio base station and the mobile device is accordingly performed. Change (for example, by lowering the transmission priority to the mobile station or by canceling the scheduling resource allocation to the mobile station).

  As a further aspect, the present technology may further include providing information to a neighbor relation list handler by a serving radio base station.

  In the usage situation or environment shown in one example, the candidate radio base station belongs to a GERAN radio access network, and the serving radio base station belongs to another radio access technology (eg, UTRAN). Conversely, in the usage situation or environment shown in another example, the candidate radio base station belongs to the UTRAN radio access network and the serving radio base station belongs to another radio access technology.

  In another of its aspects, the present technology relates to a mobile device configured for wireless operation in a communication system including a serving radio base station and a candidate radio base station. A mobile station (MS) comprises one or more transceivers and a mobile station measurement communication function. The one or more transceivers are configured to perform wireless communication between the mobile device and the serving radio base station and between the mobile device and the candidate radio base station. The mobile device measurement communication function is configured to acquire information from the candidate radio base station during at least one read gap, and the information is information for identifying a cell global ID (CGI) of the candidate radio base station, Or it is the cell global ID (CGI) itself of the radio base station. In one embodiment, the mobile device measurement communication function obtains a first type of information from the candidate radio base station during at least one read gap and a second from the candidate radio base station during at least another read gap. Each reading gap is a period in which the mobile device does not receive information from the serving radio base station.

  In another of the aspects, the present technology relates to a base station configured for wireless operation in a communication system including a mobile station in addition to a serving radio base station and a candidate radio base station. The base station includes a transceiver and a base station measurement communication function. The transceiver is configured to perform radio transmission between the mobile device and the serving radio base station and between the mobile device and the candidate radio base station. The base station measurement communication function allows the mobile device to acquire information from candidate radio base stations in at least one reading gap, and the information is information for specifying the cell global ID (CGI) of the candidate radio base station. Or the cell global ID (CGI) of the radio base station itself. In one embodiment, the base station measurement communication function allows the mobile device to obtain a first type of information from candidate radio base stations in at least one read gap, and allows the mobile device to acquire at least another one read gap. The second type of information is permitted to be acquired from the candidate radio base stations, and each reading gap is a period in which the mobile device does not receive information from the serving radio base station.

  In some examples of embodiments, a two-stage information acquisition procedure may be used to obtain the final required information (eg, cell global ID (CGI)) of the candidate base station. In the two-stage information acquisition procedure, first type information is first acquired from a candidate base station. The first type of information is used to determine how to acquire the second type of information (for example, information that is finally required such as CGI) from the candidate base station. Thus, in an example embodiment and mode of implementation, the method comprises operations including the following operations. (A) The mobile device acquires the first type information from the candidate radio base station during at least one read gap (the read gap is a period in which the mobile device does not receive information from the serving radio base station) A), (b) using the first type of information to determine how to obtain the second type of information broadcast from the candidate radio base station, and (c) the serving radio The base station allows the mobile device to obtain a second type of information broadcast from the candidate radio base station, and (d) the mobile device receives a second from the candidate radio base station during at least another one read gap. Get information of type.

  In the embodiments and methods described above, the first type of information identifies synchronization information of candidate radio base stations, local identification information of candidate radio base stations, or cell global ID (CGI) of candidate radio base stations. Or the cell global ID (CGI) itself or one or more thereof.

  The foregoing and other objects, features and advantages of the present invention will become apparent from the following more detailed description of the preferred embodiment, taken in the accompanying drawings, wherein the reference characters indicate the same parts in all of the various figures. It will be. The figures are not necessarily scaled at a constant rate, but instead emphasized to clarify the principles of the present invention.

1 is a diagram of a communication system operating with both a first radio access network having a first type of radio access technology and a second radio access network having a second type of radio access technology. FIG. 1 is a diagram of a communication system operating with both a first radio access network having a first type of radio access technology and a second radio access network having a second type of radio access technology. FIG. FIG. 6 is a simplified functional block diagram illustrating an example aspect of a representative mobile terminal and radio access network node involved in an example inter-RAT / inter-frequency handover. Serving radios related to measurements performed to detect and identify adjacent base stations between RATs / inter-frequency where the serving radio base station and the candidate radio base station belong to different RATs and / or frequencies It is a diagram which shows communication between a base station, a mobile device (MS), and a candidate radio base station. The mobile station (MS) cannot receive from the serving radio base station during the read gap, and the mobile station (MS) has a higher required bandwidth than the mobile station with a lower required bandwidth (for example, the mobile station A). FIG. 6 is a diagram illustrating that the quality of service (QoS) (bandwidth and / or latency) of a mobile device with a high number of requests (eg, mobile device B) may be significantly reduced. It is a graph which shows that the inter-RAT / inter-frequency measurement threshold may be set higher than the corresponding handover threshold. FIG. 6 is a diagram illustrating an example embodiment and mode of implementation that is an example (eg, a bad scenario) where the transmission gap is set long enough to find the desired information. FIG. 9 is a diagram illustrating an example embodiment and mode of implementation in which a transmission gap occurs until the desired information is obtained and reported (in FIG. 8, a mobile station (MS) and a serving wireless base; The signaling delay with the station is removed, but the end of the transmission gap will be slower than shown in FIG. FIG. 6 is a diagram illustrating an example embodiment and mode of implementation using a sliding transmission gap. It is a flowchart which shows the exemplary representative operation | movement or step regarding the two-step information acquisition procedure which is an example. The serving radio base station and the candidate radio base station belong to different RATs and / or frequencies, and in particular the mobile station (MS) measures the frame number or scheduling information related to the information broadcast from the candidate BS, and the candidate Inter-RAT / inter-frequency neighbor base station detection and identification that calculates the time interval at which the radio base station CGI is transmitted and informs the serving RAT when the Cell Global ID (CGI) is measured FIG. 2 is a diagram illustrating communication between a serving radio base station, a mobile station (MS) and a candidate radio base station related to measurements performed for The serving radio base station and the candidate radio base station belong to different RATs and / or frequencies, in particular, the mobile station (MS) measures the frame number of the scheduling information, and the serving radio base station Calculate the time interval at which the cell global ID (CGI) of the candidate radio base station is transmitted, and notify the mobile station (MS) when the cell global ID (CGI) should be measured using a specific method, RAT FIG. 2 is a diagram illustrating communication between a serving radio base station, a mobile station (MS) and a candidate radio base station in relation to measurements performed for detection and identification of adjacent base stations between and between frequencies . Graph diagram showing signal quality when a mobile station (MS) moves from the coverage of a serving radio base station to the coverage of a candidate radio base station having a different radio access technology (RAT) and / or a different frequency It is. When performing inter-RAT / inter-frequency measurements, it shows how the mobile station (MS) may alternate between serving radio base stations and candidate radio base stations, in particular reading It is a diagram which shows the case where a gap generate | occur | produces with a fixed period and the gap length does not change. FIG. 2 is a diagram illustrating scheduling in E-UTRAN where resources are allocated to a mobile station (MS) both in frequency and time.

  In the following description, specific details are set forth, such as particular architectures, interfaces, techniques, etc., for purposes of explanation and not limitation, as a means of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. That is, those of ordinary skill in the art will be able to embody the principles of the present invention and devise various arrangements that fall within the spirit and scope thereof, although not explicitly described or illustrated herein. . In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail. All statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Further, such equivalents are intended to include both currently known equivalents and any development element that performs the same function regardless of equivalents or structures developed in the future.

  Thus, for example, those skilled in the art will appreciate that the block diagrams herein may represent schematic diagrams of illustrative circuits embodying the principles of the technology. Similarly, flow diagrams, state transition diagrams, pseudocode, and the like are substantially represented on a computer-readable medium, whether or not a computer or processor is explicitly illustrated. It will also be understood to represent various processes that may be performed by such a computer or processor.

The functions of the various elements, including the functional blocks named or described as “processors” or “controllers”, are achieved through the use of dedicated hardware and through the use of hardware capable of executing software in conjunction with appropriate software. May be provided. When provided by a processor, functionality may be provided by a single dedicated processor, by a single shared processor, or by multiple individual processors, some of which may be shared or distributed. Furthermore, the explicit use of the terms “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, but as digital signal processor (DSP) hardware, read-only for software storage. Memory (ROM), random access memory (RAM), and non-volatile storage may be included, but are not limited to these.
1.0 Overview 1.1 Structural Overview Example FIG. 1 illustrates an example communication system 10 that operates with both a first radio access network 12 and a second radio access network 14. In the communication system 10 as an example of FIG. 1, a first radio access network 12 has a first type of radio access technology (RAT), and a second radio access network 14 has a second type of radio. Has access technology. In the non-limiting example shown in FIG. 1, it happens that the first radio access network 12 uses GERAN radio access technology, whereas the second radio access network 14 is UTRAN (or E-UTRAN). Uses wireless access technology. Both the first radio access network 12 and the second radio access network 14 are connected to an external core network 16, which is (for example) a public switched telephone network (PSTN) or an integrated services digital network (ISDN). Or both. The core network 16 may include or be accessible to a neighbor list (NRL) handler 18.

  The first radio access network 12 and the second radio access network 14 each include a radio base station that is generically called a “base station”. Depending on the situation, a base station controller (one or more base station controllers ( BSC) or a control node such as a radio network controller (RNC). Whether one or both of the first radio access network 12 and the second radio access network 14 have a control node depends on the specific architecture of the particular radio access network. Some radio access networks (such as E-UTRAN) have an essentially flat structure achieved by removing the control node and integrating various functions into the base station, as previously described. Because. In the particular example shown in FIG. 1, for purposes of explanation, it is assumed that the first radio access network 12 is a GERAN type radio access network and the second radio access network 14 is UTRAN. A management node is shown (although it is a dashed line to show its presence in some types of radio access networks).

For this reason, the first radio access network 12 includes one or more base station controllers (BSC) 26 _G , and each base station controller (BSC) 26 _G includes one or more base stations. (BTS) 28 _G is controlled. In the example shown in FIG. 1, the base station controller (BSC) 26 _G is connected to two base stations, specifically, a base station (BTS) 28 _G-1 and a base station (BTS) 28 _G-2 . Each base station (BTS) 28 _G is depicted in FIG. 1 as serving three cells C. Each cell C is represented by a circle adjacent to the respective base station. Thus, those skilled in the art will understand that a base station may provide communication services over an air interface to more than one cell, and different base stations may provide services to different numbers of cells. . Base station controller (BSC) 26 _G is such a cell C _G shown example in Figure 1, controls the radio resources and radio connectivity within a set of cells. Each base station (BTS) 28 _G handles radio transmission and reception within one or more cells.

The second radio access network 14 has one or more radio network controllers (RNC) 26 _U. For simplicity, UTRAN 14 in FIG. 1 is shown as having only one RNC node, but usually more than one such node is often provided. The RNC node 26 _U is connected to a plurality of base stations (BS) 28 _U. For example, again for simplicity, two base station nodes, base station (BS) 28 _U-1 and base station (BS) 28 _U-2 are shown connected to RNC 26 _U. . It will also be appreciated that different numbers of base stations may be served from the RNC, and the RNC need not serve the same number of base stations. Like the GERAN network 12, in the UTRAN network 14, for simplicity, each base station 28 _U is shown serving three cells (each of which is at least partially It has been named C _U). In the second radio access network (UTRAN network) 14, a radio network controller (RNC) 26 _U is, with respect to controlling radio resources and radio connectivity within a set of cells C _U, the base station (BS) 28 _U handles radio transmission and reception within one or more cells.

FIG. 1 shows a wireless mobile device (MS) 30. As used herein, the term “mobile station” encompasses both the concept of a mobile station and the concept of a user equipment unit (UE), as well as other concepts, as previously described. As described herein, one of the base stations in one of the radio access networks (either the first radio access network 12 or the second radio access network 14) is connected to a mobile device (MS) 30. Another one of the other radio access network base stations that serve as a serving base station may be a candidate radio base station for a mobile station (MS) 30. Thus, for example, the cell C _{G-2-3 of} the first radio access network 12 may be a serving base station for the mobile station (MS) 30, but considering the proximity and / or reception, the cell C _U-1-1 may be a candidate base station. The reverse can also happen.

  FIG. 2 shows another example communication system 10 'that operates with both a first radio access network 12' and a second radio access network 14 '. In the communication system 10 ′ of the example of FIG. 2, the first radio access network 12 ′ operates at the first radio frequency (f1), whereas the second radio access network 14 ′ operates at the second frequency ( Operates in f2). As in the example of FIG. 1, both the first radio access network 12 ′ and the second radio access network 14 ′ are connected to the external core network 16, and the external core network 16 includes an adjacency list ( NRL) handler 18 may be provided or accessible.

The first radio access network 12 ′ may include one or more base station controllers (BSC) 26 _1f in some circumstances, and each base station controller (BSC) (when deployed), similar to FIG. ) 26 _1f can control one or more base stations (BTS) 28 _1f, a base station (BTS) 28 _1f serves a cell C _1f. Similarly, the second radio access network 14 ′ may include one or more radio network controllers (RNCs) 26 _2f in some circumstances, and each RNC node 26 _2f (when deployed) services cell C _2f. Connected to one or more serving base stations (BTS) 28 _2f .

  The techniques described herein include the inter-RAT type operation depicted in FIG. 1 (with different radio access technology type radio access networks) and the FIG. 2 (with different radio frequency radio access networks). It should be understood that it relates to one or both of the inter-frequency types of operations that are performed. For this reason, the inclusive naming between RATs / frequency is adopted. The entire description below, including reference to the following figures, encompasses both types of operations, eg, both between RATs and frequencies, unless specifically stated otherwise or apparent from the context.

In view of the applicability of the technique to both inter-RAT and inter-frequency operation, FIG. 3 generally illustrates the serving base station 28 _S and candidate radio base station 28 _C. While serving base station 28 _S may belong to one type of radio access technology, candidate radio base station 28 _C may belong to another type of radio access technology. In such an example, what types of different radio access technologies are employed in the radio access network of the serving base station 28 _S and candidate base station 28 _C will be slightly different for the purposes of FIG. Makes no difference. Alternatively, the serving base station 28 _S may belong to a radio access network (or base station) operating at the first frequency, whereas the candidate radio base station 28 _C may be at the first frequency. It may belong to a working radio access network (or base station). FIG. 3 shows that a serving base station 28 _S and a candidate radio base station 28 _C are connected to a control node, such as a BSC / RNC type node (specifically, nodes 26 _S and 26 _C respectively). Which indicates that. FIG. 3 shows selected general aspects of the mobile station (MS) 30 and selected functions of the serving base station 28 _S and candidate base station 28 _C.

A mobile device (MS) 30 shown in FIG. 3 includes a data processing control unit 31 that controls various operations required by the mobile device (MS) 30. The data processing control unit 31 of the mobile device (MS) 30 has a mobile terminal inter-RAT / inter-frequency handover function 40 and a measurement communication function 42, and their uses will be described in more detail later. Further, the data processing control unit 31 provides a control signal and data to the wireless transceiver 33 connected to the antenna 35. The measurement communication function 42 communicates with the serving base station 28 _S and the candidate radio base station 28 _C involved in requesting or obtaining measurements or information (eg, measurements or information for potential handover purposes). Control communication. The inter-RAT / inter-frequency handover function 40 is actually called when a handover execution decision is made.

By way of example and not exhaustive description, both the serving base station 28 _S and the candidate base station 28 _C shown in FIG. 3 comprise a base station data processing controller 36, which includes one or more base station transceivers. (TX / RX) 38 is connected. Each base station transceiver (TX / RX) 38 is connected to a corresponding antenna 39 and communicates with a mobile device (MS) 30 through an air interface by an appropriate antenna in the antenna 39.

Each data processing control unit 36 of the providing base station 28 _S and the candidate radio base station 28 _C includes an inter-RAT / inter-frequency handover function 50 and a measurement communication function 52. For example, the serving base station 28 _S includes the inter-RAT / inter-frequency handover function 50 _S and the measurement communication function 52 _S , while the candidate base station 28 _C includes the inter-RAT / inter-frequency handover function 50 _C. And a measurement communication function 52 _C. At each base station, each measurement communication function 52 communicates with a mobile station (MS) 30 to request or obtain measurements or information (eg, measurements or information for potential handover purposes). The inter-RAT / inter-frequency handover function 50 is called when the handover execution decision is made.

Any or all of the mobile terminal inter-RAT handover function 40, or the measurement communication function 42, or the inter-RAT / inter-frequency handover function 50, or the measurement communication function 52 is an expanded representation of the terms controller and processor herein. Therefore, a controller or a processor may be provided. These functions are not specifically mentioned at the exact time of the description, but are involved in performing the operations described herein and are briefly summarized above.
1.2 Operational Example Overview FIG. 4 illustrates certain exemplary non-limiting basic operations and steps with inter-RAT / inter-frequency measurement scenarios. An inter-RAT / inter-frequency measurement by a mobile station selected using the trigger conditions described in section 2.0 indicates that the new inter-RAT / inter-frequency adjacent base as shown in action (1) of FIG. Used to detect stations. For example, it may be evaluated at the base station (BS) or mobile station (MS) whether actual trigger conditions with rules and thresholds are met. In the case of the base station (BS), the base station (BS) receives the measurement value from the mobile device (MS) and evaluates whether the trigger condition is satisfied. In the case of a mobile device (MS), the base station (BS) notifies the mobile device (MS) of the trigger condition, evaluates whether the mobile device (MS) satisfies the condition, and if the trigger condition is satisfied. Immediately start inter-RAT / inter-frequency measurement. In the measurement configuration (operation (1) in FIG. 4) transmitted from the base station (BS) to the mobile station (MS), information necessary for the base station (BS) to perform the measurement (for example, regarding the GERAN BS). May include an absolute radio frequency channel number (ARFCN), and for UTRAN BSs, an ARFCN and scrambling code).

  The mobile station (MS) measures the base station signal quality between surrounding RATs / frequency as soon as the trigger conditions in section 2.0 are met. During the read gap (described above), measurements are made as shown in operation (2a) of FIG. 4 and (as shown in operation (2b) of FIG. 4) each measurement result is transmitted to the base station (BS ) Is reported to the serving base station (BS). The local ID may take the form of, for example, a base station ID code (BSIC) for GERAN and a scrambling code for UTRAN.

  When the serving base station (BS) does not have prior knowledge about the neighboring base station (BS) having the reported local ID, the serving base station (BS) performs the operation (3) in FIG. As shown in FIG. 4, a CGI measurement request may be transmitted to the mobile station (MS). As shown in operation (4b) of FIG. 4, the mobile station (MS) may use one of the candidate radio base stations (BS), eg, using one of the embodiments and implementation modes presented in section 3.0. Measure the cell global ID (CGI) and report the cell global ID (CGI) to the serving base station (BS) (as shown in action (4a)). In an example embodiment, the mobile device measurement communication function 42 may measure the cell global ID (CGI) of the candidate base station (BS) as in operation (4b) of FIG. 4 and the operation of FIG. It may be configured to send and receive communications consisting of the operations of FIG. 4 including a cell global ID (CGI) report to a serving base station (BS) as in 4a). In an exemplary embodiment, the base station measurement communication function 52 transmits and receives communication as shown in FIG. 4 and allowing or allowing the mobile station to perform the operations of FIG. It may be configured.

Based on the inter-RAT / inter-frequency measurement report and information retrieved from the lookup, candidate radio base stations (BS) may be added to the serving base station (BS) neighbor relation list (NRL). As shown in the operation operation (5) of FIG. 4, the service providing base station (BS) is the operation support system (OSS) or any other management node for the newly detected candidate radio base station (BS). May be notified to the NRL handler. As shown in operation (6) of FIG. 4, the NRL handler notifies the candidate radio base station (BS) about the new adjacency relationship. When so notified, the candidate base station (BS) adds an entry in its NRL corresponding to the serving base station (BS).
2.0 Inter-RAT / Inter-frequency Measurement Triggers Various trigger criteria are possible for inter-RAT / inter-frequency measurements. Proposed criteria include, but are not limited to:
a) A low data rate mobile station performs inter-RAT / inter-frequency measurements. Retransmission due to poor channel quality may actually transmit more data than is required for mobile station (MS) service. Therefore, the criteria for selecting a mobile for measurement must be based on the UL and DL data rates actually transmitted with the mobile (MS).
b) A mobile device whose signal quality estimate of the serving base station (BS) falls below a given threshold (see threshold C in FIG. 6) performs inter-RAT / inter-frequency measurements.

  Considering the above criteria, for example, from the description with reference to FIG. 15, the scheduling block (SB) is the smallest scheduling entity, and the base station (BS) transmits UL and DL transmissions including retransmissions for a specific mobile station (MS). Remember that you may control. When performing inter-RAT / inter-frequency measurements, the impact on services, such as video streaming, is smaller for mobiles with fewer required scheduling blocks (SB), as shown in FIG. Under such circumstances, a mobile station with a small average number of scheduled scheduling blocks (SB) should perform inter-RAT / inter-frequency measurements.

  The threshold used in criterion b) may be the same threshold used for inter-RAT / inter-frequency handover measurement (eg, threshold A in FIG. 6), and the mobile station (MS) goes out of service area. It may be set above the handover threshold (eg, above threshold A in FIG. 6, to threshold C in FIG. 6, etc.) to ensure that adjacent base stations between RATs / inter-frequency are found before.

  The use of trigger criteria a) and b) and the threshold settings used in criteria b) may vary in different situations. For example, a newly deployed base station (BS) may have many unknown neighbor base stations, and both options a) and b) could be used to find them quickly. In newly deployed base stations (BS), it may be appropriate to set the inter-RAT / inter-frequency threshold (C in FIG. 6) higher than the handover (HO) measurement threshold. For base stations (BS) that have been in the network for a considerable period of time, it may be assumed that most of the neighboring base stations have already been found, and it is sufficient to use only criterion b) with the same threshold as for handover measurements Sometimes.

Further, the threshold C may depend on the service, contract type, UE type, and the like. For example, gold contract users are assigned a lower threshold C than regular contract users to avoid a larger range of bulk measurements.
3.0 Cell Global ID (CGI) Measurement Assume that a mobile station (MS) reports another RAT / frequency candidate base station (BS) and that the serving base station (BS) requests CGI measurement. (Operation 3 in FIG. 4). In order to measure the cell global ID (CGI) of another RAT / frequency base station (BS), the mobile station (MS) again matches the frequency of that base station (MS) to the desired RAT / frequency desired. Listening to the serving RAT / frequency must be stopped for the time required to measure the information. In order to obtain a candidate base station (BS) cell global ID (CGI), it may be necessary to first obtain synchronization, then to obtain the actual time at which the CGI is transmitted, and finally CGI Can be measured. The present technology proposes a number of different ways to handle the measurement of information transmitted from different RAT / frequency base stations (BSs), eg different embodiments and modes. As used herein, a “measurement value” may refer to any and all information entities or information types that must be known to obtain a cell global ID (CGI), such as synchronization and local IDs. As a result, embodiments and implementation modes may be used to measure not only cell global ID (CGI) but also any information transmitted from different RAT / frequency base stations (BS).
3.1 First Embodiment / Mode (Method a)
In the first embodiment and mode shown in FIG. 7, also known as “method a” or “solution a”, the serving base station (BS) emits a transmission gap of length T. Here, T is the worst case time for obtaining desired information from the candidate base station (BS). During this gap, the mobile station (MS) measures the desired information. Note that this solution requires the serving base station (BS) to know the worst case time T.

In a variation of the first embodiment and mode, also known as “Method d” or “Solution d”, the mobile station (MS) is informed to the base station (BS) when measuring during a length T read gap. Notice. The serving base station (BS) provides a transmission gap during this period. This method is a subset of method a), but in this case the mobile station (MS) leads the transmission gap.
3.2 Second Embodiment / Mode (Method b)
In the second embodiment and mode shown in FIG. 8, also known as “method b” or “solution b”, the serving base station (BS) sends a measurement request to the mobile station (MS). Immediately after that, a transmission gap is started. During this gap, the mobile station (MS) measures the desired information. The transmission gap ends as soon as the serving base station (BS) receives the measurement result from the mobile station (MS). The gap will have a maximum length T. T in this case is the worst case time for obtaining the desired information. In contrast to solution a), the length T must not be known in advance.

In a variant of the second embodiment and mode, also known as “method e” or “solution e”, the mobile station (MS) immediately after transmitting a transmission gap message to the serving base station (BS). To start a read gap. The base station (BS) issues a transmission gap that ends as soon as the base station (BS) receives the measurement result from the mobile station (MS). This method is similar to method b), but in this case the mobile station (MS) leads the transmission gap.
3.3 Third Embodiment / Mode (Method c)
In the third example embodiment and mode shown in FIG. 9, also known as “method c” or “solution c”, a base station (BS) serving a fixed-length transmission gap periodically emits. The mobile station (MS) then measures the desired information. It is assumed that desired information is transmitted periodically. Under certain conditions, the transmission gap will slide towards the broadcast frame for the desired information and eventually line up with one of these broadcast frames.
3.4 Fourth Embodiment / Mode (Method f)
In a fourth embodiment and mode, also known as “method f” or “solution f”, the mobile station (MS) emits a read gap to perform inter-RAT / inter-frequency measurements, but provides service. Do not report this to the serving base station (BS) and ignore serving RAT / frequency transmissions during this time. Cannot contact mobile station (MS) during inter-RAT / inter-frequency measurements. The network will experience the same behavior as if the mobile (MS) passed through the shadow area.

  The serving base station (BS) ensures that the mobile station (MS) does not assign SB (DL and UL transmission) to the mobile station (MS) when performing inter-RAT / inter-frequency measurements. May be. Methods a) -e) ensure that DL and UL transmissions do not occur during the time interval in which the mobile station (MS) is measuring another RAT / frequency, and therefore the serving RAT / frequency. Cannot communicate with. The methods a) to c) are performed when the serving base station (BS) starts, and the serving base station (BS) is the time during which the mobile station (MS) is performing inter-RAT / inter-frequency measurement. I know the interval. In the methods d) to e), the mobile device (MS) starts, and the mobile device (MS) notifies the serving base station (BS) that the mobile device performs inter-RAT / inter-frequency measurement.

Method f) may lead to loss of radio frames because the mobile station (MS) suddenly changes frequency to perform inter-RAT / inter-frequency measurements. However, this is not considered a serious problem since lost frames are recovered using hybrid automatic repeat request (HARQ). The mobile station (MS) may be configured to transmit the CQI report to the base station (BS). A mobile station (MS) performing inter-RAT / inter-frequency measurements may not be able to send certain reports (eg, CQI reports and (N) ACKs) to the serving RAN. Also, the base station (BS) knows that the mobile station (MS) stops listening to the serving base station (BS) at an unknown time in order to perform inter-RAT / inter-frequency measurements. Yes. Therefore, a certain report (for example, CQI report) has not been received from a certain mobile station (MS), or a measurement request has been requested from the same mobile station (MS) (having not yet sent measurement results) , Or both, may be used as an indication that the mobile station (MS) is currently performing an inter-RAT / inter-frequency measurement. Under such circumstances, the scheduler may be configured to lower the priority of transmission to the mobile station (MS) or not allocate any scheduling block (SB) to the mobile station (MS). . The result is that the drop probability of the radio frame to the mobile station (MS) performing the inter-RAT / inter-frequency measurement is lowered, and the scheduler assigns the SB to another mobile station (MS). That's good.
4.0 Measurement Enhancement / Modification In some example embodiments, a two-stage information acquisition procedure is used to obtain the final required information (eg, cell global ID (CGI)) of a candidate base station. May be. In the two-stage information acquisition procedure, first type information is first acquired from a candidate base station. The first type of information is used to determine how to acquire the second type of information (for example, information that is finally required such as CGI) from the candidate base station.

  FIG. 10 illustrates exemplary representative operations or steps involved in an exemplary two-stage information acquisition procedure. Act 10-1 comprises the mobile station obtaining a first type of information from the candidate base station during at least one read gap. The first type of information may be any information that facilitates the determination of how to obtain the second type of information. For example, the first type of information may be a frame number broadcast from a candidate base station or scheduling information. The read gap of operation 10-1 is a period during which the mobile device does not receive information from the serving radio base station. In one embodiment of the procedure of FIG. 10, the serving base station permits the mobile station to obtain the first type of information broadcast from the candidate radio base station.

  The operation 10-2 of the two-stage information acquisition procedure, which is an example of FIG. 10, uses the first type information to acquire the second type information broadcast from the candidate radio base station. The step of determining. The decision may be made by a mobile station (MS) (as in the embodiment described below with respect to FIG. 11) or a serving base station (as in the embodiment described below with respect to FIG. 12). .

  The operation 10-3 of the two-stage information acquisition procedure which is an example of FIG. 10 is a step in which the base station that provides the service permits the mobile device to acquire the second type of information broadcast from the candidate radio base station. Prepare. As used herein, the step of “permitting” the serving base station to obtain the second type of information from the mobile station includes the second base type of service from the serving base station to the mobile station. Although at least one embodiment may include permitting or authorizing acquisition of information, the serving base may be used to obtain information from candidate base stations, although the mobile is authorized or authorized. Transmission from the station may be ignored. Act 10-4 comprises the mobile station obtaining a second type of information (eg, cell global ID (CGI)) from the candidate radio base station during at least another read gap.

  One or a combination of the methods presented in Section 3.0 may be used to measure the desired information from the base station at other RAT / frequency. Further, the first type of information (eg, obtained in operation 10-1 of FIG. 10) may be obtained using one of the methods of section 3.0 (eg, The second type of information (obtained in 10 operations 10-4) may be obtained using another (different) method among the methods of Section 3.0. In other words, the same method need not be used to obtain the first type of information and the second type of information (used to help identify the second type of information).

  Inter-RAT / inter-frequency when using synchronization information and possibly other measurement information from candidate base stations (BS) to find the interval at which desired information such as cell global ID (CGI) is transmitted Measurements can reduce interference to transmission traffic to the serving base station (BS). This information may be used for this given time only, for example, method a) or b) described in Section 3.1 and Section 3.2, so that Less or no interference to ongoing traffic at RAT / frequency. If you do not yet know the synchronization of the candidate base station (BS), you may find it using one of the methods a) -f) described in section 3.0.

  Operation 10-2 of FIG. 10 involves the use of the first type of information to determine how to obtain the second type of information broadcast from the candidate radio base station. The determination of how to obtain the second type of information is based on the current frame number and possibly the measurement result (first type information) such as scheduling information, by the mobile station (MS), Or it may include the calculation of the transmission time interval for the desired information, which may be performed by the serving base station (BS), provided that the necessary information is reported from the mobile station (MS).

  FIG. 11 shows an example scenario in which the mobile station (MS) notifies the serving base station (BS) of the time interval using the inter-RAT / inter-frequency measurement method. For example, operation 1 in FIG. 11 shows a step in which a mobile station (MS) acquires a frame number or scheduling information from a candidate base station. Operation 2 in FIG. 11 is that the mobile station (MS) uses a certain method (generally represented as method “X” in FIG. 11) that the mobile station (MS) is specific to the serving base station. Represents a step of notifying that CGI is measured during the time interval (represented by the time interval “[a, b]” in FIG. 11). Operation 3 in FIG. 11 shows a step of actually measuring or acquiring the CGI of the candidate base station during the time interval notified by the mobile station (MS) in operation 2 in FIG. The operation 4 in FIG. 11 represents a step of notifying the CGI acquired as a result of the operation 3 in FIG.

  FIG. 12 shows another example scenario, in particular a scenario in which a serving base station (BS) indicates to a mobile station (MS) the time interval at which the inter-RAT / inter-frequency measurement method should be used. Operation 1 in FIG. 12 shows a step in which a mobile station (MS) acquires a frame number or scheduling information from a candidate base station. Operation 2 in FIG. 12 represents a step in which the mobile station (MS) notifies the candidate base station information such as frame number, scheduling information, time alignment, etc. to the serving base station. Operation 3 in FIG. 12 shows that the serving base station uses a method specific to the mobile station (MS) (generally represented as method “X” in FIG. 12) for a certain designated time. FIG. 11 represents the step of instructing to measure CGI during the interval (represented by the time interval “[a, b]” in FIG. 12). Operation 4 in FIG. 12 shows a step in which the mobile station (MS) actually measures or acquires the CGI of the candidate base station during the time interval indicated in operation 3 in FIG. Operation 5 in FIG. 12 shows a step in which the mobile station (MS) notifies the CGI acquired as a result of operation 4 in FIG. 12 to the serving base station.

As a further alternative, as proposed in the method of section 3.4, the mobile station (MS) may decide not to inform the base station (BS) about the time interval and may simply start measuring the desired information. .
5.0 Example 5.1 First Example A first example of cell global ID (CGI) measurement of a base station (BS) at another RAT / frequency will now be described. Assume that the trigger conditions outlined in Section 2.0 are satisfied and that the mobile station (MS) starts inter-RAT / inter-frequency measurements. In this case, the mobile station (MS) may need to measure the signal quality of the candidate base station (BS) synchronously. This is done in the currently described embodiment using method c) of section 3.3 with a sliding transmission gap. The serving base station (BS) may request the mobile station (MS) to measure the cell global ID (CGI) of the candidate base station (BS), that is, operation 3 in FIG. If the mobile station (MS) does not know when the candidate base station's cell global ID (CGI) will be transmitted in this state, the mobile station (MS) will schedule using method f) of section 3.4. Get information. Scheduling information may be based on a frame number (eg, as seen in GERAN) or other explicit scheduling information broadcast from a candidate base station (BS) (eg, as seen in UTRAN). . The mobile station (MS) then calculates the time interval over which the candidate base station (BS) CGI is transmitted and measures the CGI using method f), which is in service during the measurement time. Means to ignore transmissions by RAT / frequency.
5.2 Second Example The second example relates to retrieving a CGI from a GERAN BS while connected to another RAT / frequency. In GERAN, CGI is transmitted on BCH. The TDMA frame number for transmitting the CGI is specified in 3GPP TS 45.002 “Multiplexing and multiple access on the radio path”. For example, using method c) (with section 3.0) with a sliding transmission gap, the FCCH for fine tuning and the SCH for synchronization may be measured. Upon reading the SCH, the mobile station (MS) will know the current frame number. If the mobile maintains synchronization with the GERAN base station (BS), it has measured the local ID, so the current frame number is already known and the mobile needs to make additional measurements of FCCH and SCH. There will be no.

As soon as the current frame number is known, the mobile station (MS) can calculate the time interval for measuring the CGI. This measurement is made using, for example, method f) (in section 3.4), ie the mobile station (MS) measures the CGI of the GERAN base station (BS) and is serving RAT during the measurement time. / Ignore transmissions by frequency. The mobile station (MS) then reports the measured CGI to the base station (BS).
5.3 Third Example The third example relates to retrieving CGI from a UTRAN base station (BS) while connected to another RAT / frequency. In UTRA, CGI is transmitted in 3GPP TS 25.331 "Radio Resource Control (RRC): Protocol specification (PRC)" as described in P-CCPCH (Primary Common Control Channel). Is done. A radio frame in which CGI is transmitted is specified in a master information block (MIB, Master Information Block), which is also transmitted by P-CCPCH. Therefore, the mobile device (MS) first reads the information contained in the MIB and then reads the CGI.

The mobile station (MS) obtains the scrambling code of the candidate base station (BS) synchronously, for example using method example c) (in section 3.3) using a sliding transmission gap. When synchronized, the mobile station (MS) starts reading the P-CCPCH and acquires a system frame number (SFN). The mobile station (MS) uses SFN to calculate the frame and time interval over which the MIB is transmitted. The mobile station (MS) reads the contents of the MIB, for example using method example f) (from section 3.4), and obtains the frame and time interval over which the CGI is transmitted. The mobile station (MS) then reads the CGI and reports the CGI to the serving base station (BS) using, for example, method example f) (in section 3.4).
6.0 Examples of Benefits Automatic management of inter-RAT / inter-frequency NRLs described herein can reduce operator costs associated with planning and maintaining the Neighbor List (NRL) required for seamless inter-RAT / inter-frequency mobility. Leading to decline. Advantages provided by the present technology include (but are not limited to):
-Little or no human intervention is required when creating an adjacency list (NRL).
-The method of presentation is based on feedback information from the mobile station, and from this situation, automatic NRL (ANRL) management reacts immediately to changes in radio propagation conditions in the cell.
-Since the present invention relies on feedback from the mobile station, it does not require a radio propagation model based on eg topology.
-Little or no traffic jams are transmitted between the mobile and the base station.
-Fewer traffic is brought into the transport network between base stations compared to previous technologies. Some previous technologies rely on base stations to continuously exchange information about mobile devices in their service areas.
-Supports inter-RAT / inter-frequency NRL, in contrast to previous known solutions that handle only one specific RAT.

  Although the foregoing description has many specificities, they should not be construed as limiting the scope of the invention, but merely as providing some illustrations of presently preferred embodiments. Should be. Therefore, it will be understood that the scope of the present invention fully encompasses other embodiments that may be apparent to those skilled in the art, and the scope of the invention is not limited accordingly. Reference to an element in the singular is not intended to mean “one and only” unless explicitly so stated, and is specifically intended to be “one or more”. All structural and functional equivalents of the elements of the above-described preferred embodiments known to those skilled in the art are expressly incorporated herein by reference and are intended to be included herein. Moreover, a device or method need not address every and every problem that the present invention is intended to solve, which is to be encompassed herein.

Claims (32)

A method of operating a communication system (10) comprising a serving radio base station (50 _S ) and a candidate radio base station (50 _C ), wherein the serving radio base station (50 _S ) A mobile station (30) is a radio base station that provides a measurement report, and the serving radio base station (50 _S ) and the candidate radio base station (50 _C ) have at least one of frequency and radio access technology. Differently
The service providing radio base station (50 _S ) authorizing the mobile device (30) to acquire information broadcast from the candidate radio base station (50 _C );
The mobile device (30) obtaining the information from the candidate radio base station (50 _C ) during at least one reading gap, wherein the information is the candidate radio base station (50 _C ); Information for identifying the cell global ID (CGI) of the mobile base station or the cell global ID (CGI) of the radio base station itself, and the reading gap is a radio for which the mobile device (30) is providing the service. And a step of not receiving information from the base station (50 _S ). The method according to claim 1, characterized in that the information is synchronization information of the candidate radio base station (50 _C ). The method according to claim 1, characterized in that the information is local identification information of the candidate radio base station (50 _C ). The wireless base station (50 _S ) that provides the service has a predetermined period during which the mobile device (30) can acquire the information from the candidate wireless base station (50 _C ) to the mobile device (30). Issuing a transmission gap having;
The method according to claim 1, further comprising the step of the mobile station (30) obtaining the information from the candidate radio base station (50 _C ) during the transmission gap. In response, the mobile device (30) notifying the serving radio base station (50 _S ) that the mobile device (30) emits the at least one read gap;
The method according to claim 4, further comprising the step of the serving radio base station (50 _S ) issuing the transmission gap for the mobile device (30). The serving radio base station (50 _S ) starts a transmission gap and allows the mobile device (30) to acquire information broadcast from the candidate radio base station (50 _C );
2. The method according to claim 1, further comprising the step of: ending the transmission gap as soon as the serving radio base station (50 _S ) receives the information from the mobile device (30). Method. Requesting the mobile station (30) to issue the transmission gap to the serving radio base station (50 _S );
The method of claim 6, further comprising the step of the mobile (30) starting a reading gap to obtain the information. The serving radio base station (50 _S ) issues a fixed-length periodic transmission gap to the mobile device (30), whereby at least one of the transmission gaps is transferred to the candidate radio base station ( having in the information broadcast from 50 _C), a step of aligning the broadcast frame of the candidate radio base station (50 _C),
The method of claim 1, further comprising: the mobile (30) obtaining the information during one of the periodic transmission gaps. The mobile unit (30) issuing the at least one read gap to obtain the information from the candidate radio base station (50 _C ); and the serving radio base station during the read gap The method of claim 1, further comprising ignoring transmissions from (50 _S ).   The method of claim 9, further comprising the step of the mobile (30) recovering frames lost during the at least one read gap using an iterative request procedure. When the serving radio base station (50 _S ) does not receive a predetermined report from the mobile device (30), it indicates that the mobile device (30) has emitted the at least one reading gap. process as that understanding, which accordingly, the radio base station in the service delivery (50 _S), changes the communication with the radio base station in the serving (50 _S) and the mobile station (30) and The method of claim 1, further comprising: The service-provided radio base station (50 _S ) lowers the priority of transmission to the mobile device (30), so that the service-provided radio base station (50 _S ) and the mobile device (30) The method of claim 11, further comprising changing the communication with. The method according to claim 11, further comprising the step of the serving radio base station (50 _S ) canceling allocation of scheduling resources to the mobile station (30). The method of claim 1, further comprising: the serving radio base station (50 _S ) providing the information to an adjacency list handler. The method according to claim 1, characterized in that said candidate radio base station (50 _C ) belongs to a GERAN radio access network and said serving radio base station (50 _S ) belongs to another radio access technology. The method according to claim 1, characterized in that said candidate radio base station (50 _C ) belongs to a UTRAN radio access network and said serving radio base station (50 _S ) belongs to another radio access technology. (A) the mobile device (30) obtaining a first type of information from the candidate radio base station (50 _C ) during at least one reading gap;
(B) using the first type of information to determine how to obtain a second type of information broadcast from the candidate radio base station (50 _C ); The mobile device (30) further comprises obtaining the second type of information from the candidate radio base station (50 _C ) during at least another one read gap. The method described. The serving radio base station (50 _S ) acquires the first type of information broadcast from the candidate radio base station (50 _C ) to the mobile device (30), and the candidate radio The method according to claim 17, further comprising the step of allowing the execution of the operation (a) to obtain the second type of information broadcast from the base station (50 _C ). The first type of information, to claim 17, wherein the candidate is at least one local identification information of the wireless base station (50 _C) of the synchronization information and the candidate radio base station (50 _C) The method described. The method according to claim 17, wherein the first type of information is information for identifying a cell global ID (CGI) of the candidate radio base station (50 _C ). The method according to claim 17, characterized in that the second type of information is a cell global ID (CGI) of the candidate radio base station (50 _C ). The operation (a) is performed using the operation of one of claims 6 to 11,
18. The method of claim 17, wherein operation (d) is performed using the operation of another one of claims 6-11. A mobile device (30) configured for wireless operation in a communication system (10) comprising a serving wireless base station (50 _S ) and a candidate wireless base station (50 _C ),
Wireless communication is performed between the wireless mobile device (30) and the serving wireless base station (50 _S ), and between the mobile device (30) and the candidate wireless base station (50 _C ). Comprising one or more transceivers (33) configured as follows:
A mobile device measurement communication function (42) is configured to obtain information from the candidate radio base station (50 _C ) during at least one reading gap, the information being stored in a cell of the candidate radio base station (50 _C ). It is information for specifying a global ID (CGI) or the cell global ID (CGI) itself of the radio base station, and the reading gap is a radio base station that the mobile unit (30) is providing the service to (30) A mobile unit (30) characterized in that it is a period during which no information is received from (50 _S ). The mobile device according to claim 23, wherein the information is synchronization information of the candidate radio base station (50 _C ). The mobile device according to claim 23, wherein the information is local identification information of the candidate radio base station (50 _C ). The mobile device measurement communication function (42) obtains a first type of information from the candidate radio base station (50 _C ) during at least one read gap and the candidate radio during at least another read gap. Configured to obtain a second type of information from a base station (50 _C ), each read gap not receiving information from the serving radio base station (50 _S ) by the mobile station (30) The mobile device according to claim 23, wherein the mobile device is a period. The mobile device according to claim 26, wherein the first type information is information for specifying a cell global ID (CGI) of the candidate radio base station (50 _C ). The mobile device according to claim 26, wherein the second type of information is a cell global ID (CGI) of the candidate radio base station (50 _C ). A base station (50) of a communication system (10) that serves as a serving base station and is configured for wireless communication with a mobile device (30),
A transceiver (38) configured to perform wireless communication between the mobile (30) and the base station;
A base station measurement communication function (52) is configured to allow the mobile device (30) to obtain information from candidate radio base stations (50 _C ) in at least one read gap, Information for specifying the cell global ID (CGI) of the candidate radio base station (50 _C ) or the cell global ID (CGI) itself of the radio base station, and the reading gap is the mobile device (30 ) Is a period during which no information is received from the service-providing radio base station (50 _S ). The base station communication function (52) allows the base station (30) to obtain a first type of information from the candidate radio base station (50 _C ) in at least one read gap, and at least another Is configured to allow acquisition of a second type of information from the candidate radio base station (50 _C ) in one read gap, each read gap being served by the mobile device (30) 30. Base station according to claim 29, characterized in that it is a period in which no information is received from the radio base station (50 _S ). The base station according to claim 30, wherein the first type of information is information for specifying a cell global ID (CGI) of the candidate radio base station (50 _C ). The base station according to claim 30, wherein the second type of information is a cell global ID (CGI) of the candidate radio base station (50 _C ).

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